SCREENING OF SELECTED RICE VARIETIES AGAINST TUNGRO DISEASE CAUSED BY Rice Tungro Viruses

Abstract

ABSTRACT

Tungro disease of rice is one of the most destructive and devastating viral disease in South Asian countries including Bangladesh that causes yield loss up to 100%. The present study was carried out to assess the selected rice varieties against tungro disease through virus-vector relationship. The field experiment was conducted in the central farm of Sher-e-Bangla Agricultural University, Dhaka-1207 and virus-vector relationship study was conducted in net house. In total, twelve aman rice varieties viz. BRRI dhan34, BRRI dhan71, BRRI dhan70, BRRI dhan87, BRRI dhan80, BR11, BRRI dhan75, BRRI dhan72, BRRI dhan51 BRRI dhan30, BRRI dhan49 and Binadhan-7 were evaluated. From the field experiment it was found that the incidence of rice tungro disease showed significant variants among the tested varieties. The highest (53.34%) disease incidence was found in BRRI dhan34 and in BR11 and the lowest in BRRI dhan51 (13.35%). There was no disease incidence found in BRRI dhan80, BRRI dhan87, BRRI dhan30, BRRI dhan49 and Binadhan-7. In control condition, tested varieties were artificially inoculated with viruliferous insect Green Leaf Hopper (GLH) at 10, 20, 25 days after inoculation (DAI) and it was noted that most of the varieties except BRRI dhan49 and Binadhan-7 were infected with tungro viruses and expressed the tungro disease symptoms. But the typical symptoms were appeared after 20 DAI. The effect of yield and yield contributing character were also studied. From the result it was revealed that among the tested varieties BRRI dhan34, BRRI dhan71 and BR11 was found susceptible, and BRRI dhan49 and Binadhan-7 was showed resistance reaction to tungro viruses. It was also found that 20 days was the optimum acquisition period for transmission of tungro viruses through GLH.